1. Field of the Invention
The present invention relates to a method for manufacturing an interior permanent magnet (IPM) rotor unit that includes a core and a plurality of permanent magnets embedded in insertion holes of the core, the IPM rotor unit or a plurality of IPM rotor units counted in the axial direction thereof forming a rotor. The present invention also relates to a magnetizing device.
2. Description of Related Art
For example, Japanese Patent Application Publication No. 2014-121116 (JP 2014-121116 A) proposes magnetizing magnetic members for magnets (magnet materials) embedded in a rotor by disposing a magnetizing part serving as a source of a magnetic field so that the magnetizing part is caused to face the end face of the rotor in the radial direction thereof (FIG. 3). Magnetic flux from the magnetizing part enters a core in the radial direction of the rotor, crosses the magnet material, and returns to the magnetizing part. The magnet material is magnetized in this manner.
For example, when the core is filled with the magnet material at high pressure, a lame force is applied radially outward to the core. In the filling of the core with the magnet material, if the magnetizing part is disposed so as to face the core in the radial direction, the core is difficult to be kept from expanding radially outward. This is partly because it is difficult to cause the magnetizing part to have a strength large enough to prevent the core from expanding radially outward.